Фазовая диаграмма системы Cr-Pd

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Cr-Pd (Chromium-Palladium) M. Venkatraman and J.P. Neumann The assessed Cr-Pd phase diagram is a composite, based on the data of [36Gru], [54Rau], [67Rau], and [81Wat]. The diagram is characterized by complete solubility in the liquid state, a very small (Cr) terminal solid solution, and a broad (Pd) terminal solid solution. At low temperatures (<600 C), two ordered intermediate phases, CrPd and Cr2Pd3, are present. Because of the slow reaction kinetics at these low temperatures, the boundaries of these two phases have not been established accurately. The homogeneity range of the CrPd phase is narrow, extending approximately from 50 to 52 at.% Pd [54Rau, 58Ger, 67Rau]. The homogeneity range of the Cr2Pd3 phase is broader, ranging from ~55 to ~75 at.% Pd [58Ger, 67Rau]. In agreement with the above given decomposition temperatures, no intermediate phases were found to exist at 1200 C [56Gre, 81Wat] and at 1000 and 800 C [81Wat]. The data for the Cr liquidus curve and for the eutectic are taken from [54Rau]; the data for the Pd liquidus and solidus curves in the range from 50 to 100 at.% Pd are taken from [36Gru]. The temperature difference between the liquidus and solidus curve is approximately 10 C in this composition range. All temperatures are converted to the IPTS-68 scale. Neither [54Rau] nor [81Wat] were able to confirm the presence of an intermediate phase at 40 at.% Pd with a maximum melting point of 1400 C observed by [36Gru]. [54Rau] suggested that the maximum found by [36Gru] was caused by oxidation of the alloys. For alloys from 5 to 40 at.% Pd, [36Gru] found a eutectic temperature of 1319 с 3 C, in good agreement with the selected value of 1315 C. Accurate determination of the solubility of Pd in (Cr) has not been carried out, but [36Gru], [54Rau], and [81Wat] indicate that the solubility at the eutectic temperature is ~1 at.% Pd. The N‚el temperature of pure Cr (311.5 K) is essentially unaffected by additions of up to 1 at.% Pd [80But]. The intermediate phases CrPd and Cr2Pd3 are ferromagnetic with a maximum Curie temperature of ~350 C [68Kus]. 36Gru: G. Grube and R. Knabe, Z. Electrochem., 42, 793-804 (1936) in German. 54Rau: E. Raub and W. Mahler, Z. Metallkd., 45, 648-650 (1954) in German. 56Gre: P. Greenfield and P.A. Beck, Trans. AIME, 206, 265-276 (1956). 58Ger: D. Gerstenberg, Z. Metallkd., 49, 476-480 (1958) in German. 67Rau: E. Raub, R. Gohle, and E. R”schel, Z. Metallkd., 58, 567-568 (1967) in German. 68Kus: A. Kussmann, K. MЃller, and E. Raub, Z. Metallkd., 59, 859-863 (1968) in German. 80But: A.K. Butylenko and V.V. Nevdacha, Dop. Akad. Nauk Ukr. RSR A, (5), 66- 69 (1980) in Ukrainian. 81Wat: R.M. Waterstrat, J. Less-Common Met., 80, P31-P36 (1981). Published in Bull. Alloy Phase Diagrams, 11(1), Feb 1990. Complete evaluation contains 1 figure, 3 tables, and 22 references. Special Points of the Cr-Pd System